I. Field of the Invention
The present invention relates generally to systems and methods for detecting plagiarism and, more particularly, to a system and method for detecting plagiarism in a set of constructed responses.
II. Discussion of the Background Art
Schools in the United States and other parts of the world have been administering standardized tests for many years. In practice, standardized tests often include some combination of multiple choice questions and questions requiring a constructed or written response.
Multiple choice questions are a convenient way to assess achievement or ability in part because an answer is chosen from a finite set of pre-constructed responses and the answer can be scored quickly and accurately using automated techniques. However, because students are presented with pre-constructed responses, it is possible for a student to guess the right answer without having a requisite level of achievement or ability. Questions requiring a student to answer by constructing a response typically cannot be answered correctly without the student having the requisite level of achievement or ability. Constructed responses are usually graded by hand because of the difficulty in accounting for all the various ways a response may be constructed. Co-pending U.S. patent application Ser. No. 12/137,213 is directed to the automated scoring of constructed responses.
One concern when evaluating an individual's performance on the constructed or written response portions of a standardized exam is the possibility of plagiarism. Plagiarism in this context is the illegal collaboration between two or more individuals to construct a response to a test question. Plagiarism is a serious offense that can have serious consequences, such as voiding a student's test score. Because the consequences of plagiarism can adversely affect an individual's academic and/or professional career, the evidence of plagiarism should be irrefutable before disciplinary action is taken against a plagiarizer.
Plagiarism is typically manually detected. This process often involved the tedious comparison of test question responses in order to pinpoint similarities. However, because of the time commitment involved in manual plagiarism detection, the process is often rushed, conducted on an ad hoc basis, or skipped entirely. The detection of plagiarism requires systematic evaluation, such as having a human read all papers form the same lab or class. This systematic review is in direct contrast to good measurement, in which papers are randomly assigned to human readers. However, plagiarism reviews are almost always conducted at the same time as scoring due to the costs associated with an independent plagiarism review.